As a light guide member that receives light through one or more side surfaces thereof and that guides the light out through one or more main surfaces, a configuration with dot-like recesses or groove-like recesses in the main surfaces as a means for diffusing the light toward the main surfaces has been often proposed (see Patent Document 1, for example).
However, light guide plates with dot-like recesses or groove-like recesses have the problem that, although brightness can be ensured in a small area in the vicinity of each recess, sufficient brightness of light cannot be ensured in a relatively wide region around each recess.